Koh Seh

{{Short description|Cambodian island in the Gulf of Thailand}}

{{Infobox islands

|name = Koh Seh

| native_name = {{lang|km|កោះសេះ}}

| sobriquet =

| image_name =

| image_size =

| image_caption =

| image_alt =

| map = Cambodia

| map_caption =

| location = Cambodia - Southeast Asia

| coordinates = {{coord|10|25|N|103|48|E|region:ID_type:isle}}

| area_km2 = 7.5

| length_km = 4.4

| width_min_km = 1.8

| width_max_km = 4.4

| coastline_km = 15

| elevation_m =

| highest_mount = meters

| country = {{flag|Cambodia}}

| country_admin_divisions_title = Province

| country_admin_divisions = Sihanoukville

| country_admin_divisions_title_1 = District

| country_admin_divisions_1 = Prey Nob

| population =

| ethnic_groups = Khmer

}}

Koh Seh (Khmer: កោះសេះ, also romanized as Kaoh Seh and its former French name Ile a l'eau) is a Cambodian island located in the Gulf of Thailand, inside Ream National Park, Sihanoukville province. It lies {{convert|1.5|km|mi|0|abbr=on}} south of Koh Thmei and around {{convert|9|km|mi|0|abbr=on}} south of the main-land of Sihanoukville's Ream commune. A {{convert|4.3|km|mi|0|abbr=on}} wide sound separates it from Phu Quoc. "Koh Seh" means Horse Island. Less than 400 meters south-west of Koh Seh lies the tiny islet of Koh Ky.

Koh Seh is uninhabited while most of its shores are fringed with mangroves.{{Cite web |url=http://www.czmcam.org/dataregionsDet.aspx?c=1&zone=7®id=3 |title=Costal Zone Management, Cambodia - Kampot |access-date=2012-02-04 |archive-date=2012-07-29 |archive-url=https://archive.today/20120729161134/http://www.czmcam.org/dataregionsDet.aspx?c=1&zone=7®id=3 |url-status=dead }} The island constitutes the south-easternmost part of Ream National Park.{{Cite web |url=http://www.marineconservationcambodia.org/About-Our-Marine-Conservation-Volunteer-Project/Marine-Research-and-Conservation-Center-Koh-Rong-Samloem-Island.html |title=Marine Research and Conservation Center Koh Rong Samloem Island |access-date=2012-02-04 |archive-url=https://web.archive.org/web/20120104093242/http://www.marineconservationcambodia.org/About-Our-Marine-Conservation-Volunteer-Project/Marine-Research-and-Conservation-Center-Koh-Rong-Samloem-Island.html |archive-date=2012-01-04 |url-status=dead }}

Koh Seh is sometimes mistaken with Koh Ach Seh, located in Kep Archipelago.